Weight for one, EBD for another.
I believe there was a post somewhere, which examined Mark Webber's choice of line through corners. While they appeared somewhat odd, they made (if memory serves) maximum use of the EBD. Red Bull changed the engine mapping software sometime late-season to mimic the effect (different throttle usage) of such a race line. At some point it was believed it was this very update that put Vettel consistently in front of Webber, but it's difficult so say how much of it was infact down to Webber's shoulder.
edit1: Can't seem to find the post. I believe it started with a comment on JAF1 and continued on the autosport forum.
This thread http://forums.autosport.com/lofiversion/index.php/t132030.html
doesn't cover the choice of racing line specifically but it does mention it in relation to retarded ignition. It was discussed on this very forum here http://www.f1technical.net/forum/viewtopic.php?f=4&t=8702
. Couple it with http://phors.locost7.info/phors18.htm
and you should have a good amount of info. I'd very much like to find you the comment mentioned above, but after half an hour on google I've given up. I destinctively remember it though.
edit2 (@raymond): Dunno what answer you're looking for then. You could say the EBD increases traction in flowing corners. Without the ever so famous comment, I won't stick my neck out, but I'd expect the EBD generally makes a racing line with slightly larger swing radius and higher speed favorable.
edit3: As for turn7, it's worth noticing quite a few people actually do hit the curb during the actual race. Secondly I imagine the cement dust laid down in turn 6 to soak up the oil from Schumacher's accident could force the drivers to change their line.